MBSINIT(3) Linux Programmers Manual MBSINIT(3)
NAME
mbsinit - test for initial shift state
SYNOPSIS
#include
int mbsinit(const mbstate_t *ps);
DESCRIPTION
Character conversion between the multibyte representation and the wide
character representation uses conversion state, of type mbstate_t.
Conversion of a string uses a finite-state machine; when it is inter
rupted after the complete conversion of a number of characters, it may
need to save a state for processing the remaining characters. Such a
conversion state is needed for the sake of encodings such as ISO-2022
and UTF-7.
The initial state is the state at the beginning of conversion of a
string. There are two kinds of state: The one used by multibyte to
wide character conversion functions, such as mbsrtowcs(3), and the one
used by wide character to multibyte conversion functions, such as wcsr
tombs(3), but they both fit in a mbstate_t, and they both have the same
representation for an initial state.
For 8-bit encodings, all states are equivalent to the initial state.
For multibyte encodings like UTF-8, EUC-*, BIG5 or SJIS, the wide char
acter to multibyte conversion functions never produce non-initial
states, but the multibyte to wide-character conversion functions like
mbrtowc(3) do produce non-initial states when interrupted in the middle
of a character.
One possible way to create an mbstate_t in initial state is to set it
to zero:
mbstate_t state;
memset(&state,0,sizeof(mbstate_t));
On Linux, the following works as well, but might generate compiler
warnings:
mbstate_t state = { 0 };
The function mbsinit() tests whether *ps corresponds to an initial
state.
RETURN VALUE
mbsinit() returns non-zero if *ps is an initial state, or if ps is a
null pointer. Otherwise it returns 0.
CONFORMING TO
C99.
NOTES
The behavior of mbsinit() depends on the LC_CTYPE category of the cur
rent locale.
SEE ALSO
mbsrtowcs(3), wcsrtombs(3)
COLOPHON
This page is part of release 3.05 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2000-11-20 MBSINIT(3)